JPH0945669A - Electrode plate for plasma etching - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode plate, for a plasma etching operation, by which carbon particles which fall onto the surface of a wafer adhere thereto are small in the etching operation, by which the etching operation is performed stably and by which an electrode can be used for many hours. SOLUTION: In an electrode plate for a plasma etching operation, glasslike carbon whose raw material is a mixture of a liquid phenolic resin and a powdery phenolic resin having a number average molecular weight of 250 to 350 and having a viscosity at 25 deg.C of 100 to 350 centipoises is used as a basic material.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【発明の属する技術分野】本発明は、プラズマエッチン
グ用電極板に関する。[0001] The present invention relates to an electrode plate for plasma etching.

【０００２】[0002]

【従来の技術】ガラス状炭素は、一般の炭素材料が有す
る軽量、耐熱性、耐食性、電気伝導性等の性質を備えて
いるほか、ガス不透過性で硬度が高い、発塵性が少ない
等の特徴を持っているところから、エレクトロニクス産
業、原子力産業、航空産業等各種の分野での広範な用途
に使用されつつある。最近は、特開昭６２−１０９３１
７号公報に記載されるように炭素粒子の脱落や付着がな
い性質を利用して、半導体集積回路を製造する際のウエ
ハーのプラズマエッチング用電極板として使用すること
が検討されている。2. Description of the Related Art Glassy carbon has the properties of ordinary carbon materials such as light weight, heat resistance, corrosion resistance, and electrical conductivity, as well as gas impermeability, high hardness, and low dust generation. Because of its characteristics, it is being used for a wide range of applications in various fields such as the electronics industry, the nuclear industry, and the aviation industry. Recently, JP-A-62-10931
As described in Japanese Unexamined Patent Publication (Kokai) No. 7, utilizing the property that carbon particles do not drop off or adhere, it is considered to be used as an electrode plate for plasma etching of a wafer when manufacturing a semiconductor integrated circuit.

【０００３】しかしながら近年の半導体集積回路は高性
能化が進み、従来には問題とされなかった、より微細な
パーティクルの発生、さらにエッチング速度の不安定等
の問題がある。プラズマエッチング用電極板に対する要
求性能は一層高度になって来ており、特にエッチング時
にウエハ面に落下し付着する炭素粒子等の粒子数の少な
いものが要求されている。However, the performance of semiconductor integrated circuits in recent years has been improved, and there are problems such as generation of finer particles and unstable etching rate, which have not been problems in the past. The required performance of an electrode plate for plasma etching is becoming more sophisticated, and in particular, an electrode plate having a small number of particles such as carbon particles which drop and adhere to a wafer surface during etching is required.

【０００４】[0004]

【発明が解決しょうとする課題】本発明は上記した要求
を満足するものである。即ち請求項１記載の発明は、エ
ッチング時にウエハ面に落下し付着する炭素粒子が少な
く、安定なエッチングができ、電極の長時間の使用が可
能なプラズマエッチング電極板を提供するものである。
請求項２記載の発明は、請求項１記載の発明の解決しよ
うとする課題において、特に電極の長時間の使用が可能
なプラズマエッチング電極板を提供するものである。請
求項３記載の発明は、請求項１記載の発明の解決しよう
とする課題において、特に安定なエッチングが可能なプ
ラズマエッチング電極板を提供するものである。The present invention satisfies the above-mentioned requirements. That is, the invention according to claim 1 provides a plasma-etched electrode plate in which carbon particles that fall onto the wafer surface during etching are small and adhered, stable etching is possible, and the electrode can be used for a long time.
The invention described in claim 2 is to provide a plasma etching electrode plate in which the electrode can be used for a long time in the problem to be solved by the invention described in claim 1. The invention according to claim 3 provides a plasma etching electrode plate capable of particularly stable etching in the problem to be solved by the invention according to claim 1.

【０００５】[0005]

【課題を解決するための手段】本発明は、数平均分子量
が２５０〜３５０であり、２５℃における粘度が１００
〜３５０センチポイズの液状フェノール樹脂と粉末状フ
ェノール樹脂の混合物を原料とするガラス状炭素を基材
とするプラズマエッチング用電極板に関する。また本発
明は、前記プラズマエッチング用電極板において、基材
の見掛け密度が１．５０〜１．５３g/cm³、不純物含有
量が２０ppm以下であるプラズマエッチング用電極板に
関する。さらに本発明は、前記プラズマエッチング用電
極板において、基材の気孔径が５μｍ以下であるプラズ
マエッチング用電極板に関する。The present invention has a number average molecular weight of 250 to 350 and a viscosity at 25 ° C. of 100.
The present invention relates to an electrode plate for plasma etching using glassy carbon as a base material, which is made of a mixture of a liquid phenol resin and a powdery phenol resin of about 350 centipoise. The present invention also relates to the above-mentioned electrode plate for plasma etching, wherein the substrate has an apparent density of 1.50 to 1.53 g / cm ³ and an impurity content of 20 ppm or less. Further, the present invention relates to the plasma etching electrode plate, wherein the pore diameter of the substrate is 5 μm or less.

【０００６】本発明では、ガラス状炭素基材として、数
平均分子量が２５０〜３５０であり、２５℃における粘
度が１００〜３５０センチポイズの液状フェノール樹脂
と、粉末状フェノール樹脂の混合物を原料とすることが
重要である。どちらか一方では成形性が低下するという
欠点がある。フェノール樹脂は、フェノール又はその誘
導体、ホルムアルデヒド等のアルデヒド類をアルカリ触
媒又は酸触媒を用いて反応させて得られるが、アルカリ
触媒下で反応させたレゾール型のフェノール樹脂が好ま
しい。ここで、前記液状フェノール樹脂の数平均分子量
が２５０未満又は３５０を超える場合は、得られる基材
の気孔が多くなりパーティクルが増加するという欠点が
ある。同様の理由で好ましい数平均分子量の範囲は２７
０〜３４０であり、より好ましい数平均分子量の範囲は
２７０〜２８０である。数平均分子量は液体クロマトグ
ラフィー法により測定できる。In the present invention, as the glassy carbon base material, a raw material is a mixture of a liquid phenol resin having a number average molecular weight of 250 to 350 and a viscosity at 25 ° C. of 100 to 350 centipoise and a powdery phenol resin. is important. One of them has a drawback that the moldability is lowered. The phenol resin can be obtained by reacting phenol or its derivative, aldehydes such as formaldehyde using an alkali catalyst or an acid catalyst, and a resol type phenol resin reacted under an alkali catalyst is preferable. Here, when the number average molecular weight of the liquid phenol resin is less than 250 or more than 350, there is a drawback that the obtained base material has many pores and particles increase. For the same reason, the preferred number average molecular weight range is 27.
0 to 340, and a more preferable range of the number average molecular weight is 270 to 280. The number average molecular weight can be measured by a liquid chromatography method.

【０００７】また、２５℃における粘度が１００センチ
ポイズ未満又は３５０センチポイズを超えると組織中に
気孔が生じる。気孔が少ないという点で好ましい範囲は
１１０〜３２０センチポイズであり、より好ましい範囲
は１１０〜２５０センチポイズである。一方、本発明に
用いる粉末状フェノール樹脂とは、液状フェノール樹脂
との相溶性が良いものであるのが好ましい。上記粉末状
フェノール樹脂を得るには、例えば液状フェノール樹脂
を用いて、気孔の発生を極力おさえるよう成形、硬化し
た後、所定の粒度に粉砕したもの等を用いることが好ま
しい。用いる原料により異なるが、前述の液状フェノー
ル樹脂を原料としてその硬化を７０〜１２０℃で行った
ものを用いるのが好ましい。ここで１２０℃を超える温
度で硬化させた場合は液状樹脂との相溶性が低下し気孔
の発生の原因となる傾向にあり、一方、７０℃未満では
十分硬化されない場合が生じ所望の粒度の樹脂が得られ
なくなる傾向にある。粉末状フェノール樹脂の粒度は重
量平均粒子径が１０〜３０μｍのものが好ましい。１０
μｍ未満では粒子同士の凝集が多くなり結果的に気孔の
発生につながる傾向にあり、一方、３０μｍを超えると
液状フェノール樹脂の遍在が生じ気孔の発生につながる
傾向にある。Further, when the viscosity at 25 ° C. is less than 100 centipoise or more than 350 centipoise, pores are generated in the tissue. A preferable range is 110 to 320 centipoise, and a more preferable range is 110 to 250 centipoise in terms of the number of pores. On the other hand, the powdery phenolic resin used in the present invention preferably has good compatibility with the liquid phenolic resin. In order to obtain the powdery phenolic resin, it is preferable to use, for example, a liquid phenolic resin, which is molded and cured so as to suppress the generation of pores and then crushed to a predetermined particle size. Although it varies depending on the raw material used, it is preferable to use the liquid phenol resin as a raw material, which is cured at 70 to 120 ° C. If the resin is cured at a temperature higher than 120 ° C., the compatibility with the liquid resin tends to be lowered, which may cause the generation of pores. Tends to not be obtained. The powdery phenolic resin preferably has a weight average particle size of 10 to 30 μm. 10
If it is less than μm, aggregation of particles tends to increase, and as a result, pores tend to be generated. On the other hand, if it exceeds 30 μm, the liquid phenol resin becomes ubiquitous and pores tend to be generated.

【０００８】数平均分子量が２５０〜３５０であり、２
５℃における粘度が１００〜３５０センチポイズの液状
フェノール樹脂と粉末状フェノール樹脂の混合比は、得
られる基材の特性及び成形性の点で、前者／後者の重量
比で１０／９０〜９０／１０が好ましく、２０／８０〜
８０／２０がより好ましく、３０／７０〜６０／４０が
さらに好ましい。得られる樹脂混合物は、硬化前に目的
とするプラズマエッチング用電極の形状に応じて所定の
形状に各種の成形方法で成形されるが特に制限はない。
所定の形状に成形した後、硬化処理をする。成形と硬化
は、縮合水等が外部に抜け易い加熱条件及び昇温速度で
行なうか又は硬化の為の触媒量を適正な量に設定して行
うことができる。加熱温度は１３０〜２００℃が好まし
い。また昇温温度は５〜３０℃／時間で行うことが好ま
しい。次いで、不活性雰囲気中（通常、ヘリウム、アル
ゴン等の不活性ガスや窒素、水素、ハロゲンガス等の非
酸化性ガスの少なくとも一種の気体からなる酸素を含ま
ない雰囲気、減圧下又は真空下）において好ましくは８
００〜１２００℃の温度、より好ましくは９００〜１１
００℃の温度で焼成し炭化する。次いで、好ましくは１
５００℃以上の温度、より好ましくは１７００℃以上の
温度で高温処理しガラス状炭素とする。The number average molecular weight is 250 to 350 and 2
The mixing ratio of the liquid phenolic resin having a viscosity of 100 to 350 centipoise at 5 ° C. and the powdery phenolic resin is 10/90 to 90/10 in terms of the weight ratio of the former / the latter in view of the characteristics and moldability of the obtained base material. Is preferred, 20 / 80-
80/20 is more preferable, and 30/70 to 60/40 is further preferable. The obtained resin mixture is molded into a predetermined shape according to the desired shape of the electrode for plasma etching before curing, but is not particularly limited.
After being molded into a predetermined shape, it is cured. Molding and curing can be performed under heating conditions and a heating rate at which condensed water or the like easily escapes to the outside, or by setting an appropriate amount of a catalyst for curing. The heating temperature is preferably 130 to 200 ° C. Further, it is preferable that the temperature is raised at 5 to 30 ° C./hour. Then, in an inert atmosphere (usually an oxygen-free atmosphere consisting of an inert gas such as helium or argon or at least one gas of a non-oxidizing gas such as nitrogen, hydrogen or halogen gas, under reduced pressure or under vacuum) Preferably 8
A temperature of 00 to 1200 ° C, more preferably 900 to 11
It is fired and carbonized at a temperature of 00 ° C. Then preferably 1
Glassy carbon is obtained by high-temperature treatment at a temperature of 500 ° C. or higher, more preferably 1700 ° C. or higher.

【０００９】得られるガラス状炭素の不純物含有量は２
０ppm以下が好ましい。不純物含有量が２０ppmを超える
と、エッチングの際にウェハを汚染する傾向にある。２
０ppm以下とするには高度に純化された黒鉛治具を用い
不活性雰囲気中（通常ヘリウム、アルゴン等の不活性ガ
スや窒素等の非酸化性ガスの少なくとも一種又はこれら
の混合ガスの雰囲気）、真空中等で焼成した後、高度に
純化した黒鉛治具及び炉を用い不活性雰囲気、真空中等
で処理すること等の方法が用いられる。なお、不純物含
有量は、ＪＩＳの黒鉛灰分測定法で測定することができ
る。The glassy carbon obtained has an impurity content of 2
It is preferably 0 ppm or less. If the impurity content exceeds 20 ppm, the wafer tends to be contaminated during etching. Two
To achieve 0 ppm or less, use a highly purified graphite jig in an inert atmosphere (usually an atmosphere of at least one kind of an inert gas such as helium and argon and a non-oxidizing gas such as nitrogen, or a mixed gas thereof), After firing in a vacuum or the like, a method of using a highly purified graphite jig and a furnace and treating in an inert atmosphere, a vacuum or the like is used. The impurity content can be measured by the graphite ash content measuring method of JIS.

【００１０】以上の方法により得られるガラス状炭素の
基材の見掛け密度は消耗速度を小さくする点で、１．５
０〜１．５５g/cm³であるのが好ましく、１．５０〜
１．５３g/cm³であるのがより好ましい。また、気孔径
は５μｍ以下であるのがパーティクルを小さくする点で
好ましく、３μｍ以下であるのがパーティクルをより少
なくする点で好ましい。なお、気孔径は、製品断面にお
ける１平方mm当たりの最大気孔径を測定することにより
求められる。なお、プラズマエッチング用電極板は、形
状未加工のガラス状炭素の基材を得た後、放電加工、超
音波加工等で所定の形状に加工して得ることもできる。The apparent density of the glassy carbon substrate obtained by the above method is 1.5 in view of reducing the consumption rate.
It is preferably 0 to 1.55 g / cm ³ , and 1.50 to
More preferably, it is 1.53 g / cm ³ . The pore diameter is preferably 5 μm or less in order to reduce the particles, and 3 μm or less is preferable in order to reduce the particles. The pore diameter is obtained by measuring the maximum pore diameter per 1 mm 2 in the product cross section. The electrode plate for plasma etching may be obtained by obtaining a glassy carbon substrate having an unprocessed shape and then processing it into a predetermined shape by electrical discharge machining, ultrasonic machining, or the like.

【００１１】以上のようにして得られるプラズマエッチ
ング用電極板は、プラズマエッチング装置に搭載され、
シリコンウェハ上の酸化膜のエッチング処理に使用され
る。プラズマエッチング用電極板を取り付けたプラズマ
エッチング装置の概略図を図１に示す。図１において、
プラズマエッチング用電極板は上部電極１に使用されて
いる。ガス吹出穴４を通ってＣＨＦ₃、ＣＦ₄等の反応ガ
スが導入され、高周波により発生するプラズマが、下部
電極２の上に設置されたシリコンウェハ３上の酸化膜を
エッチングする。プラズマエッチング用電極板の大き
さ、形状等は、搭載される装置に従い、特に制限されな
い。その一例を図２に示す。図２はプラズマエッチング
用電極板の一例の正面図である。The plasma etching electrode plate obtained as described above is mounted on a plasma etching apparatus,
Used for etching oxide film on silicon wafer. FIG. 1 shows a schematic diagram of a plasma etching apparatus equipped with an electrode plate for plasma etching. In FIG.
The electrode plate for plasma etching is used for the upper electrode 1. A reaction gas such as CHF ₃ or CF ₄ is introduced through the gas outlet 4 and plasma generated by high frequency etches an oxide film on the silicon wafer 3 placed on the lower electrode 2. The size, shape, etc. of the electrode plate for plasma etching are not particularly limited according to the device to be mounted. An example is shown in FIG. FIG. 2 is a front view of an example of the electrode plate for plasma etching.

【００１２】[0012]

【実施例】以下、本発明の実施例を説明する。 実施例１ アルカリ触媒としてアンモニアを用いて、７０℃の加熱
下１時間フェノール９４０重量部とホルムアルデヒド３
６０重量部を反応させ、表１に示す物性の液状フェノー
ル樹脂を得た。一方、粉末状フェノール樹脂は、上記樹
脂を、型に注入し５０℃で３日、７０℃で３日、９０℃
で３日乾燥硬化した後、粉砕機にて平均粒子径１１μｍ
に粉砕して得た。前記液状フェノール樹脂４０重量部
（固形分）に粉末状フェノール樹脂６０重量部を添加
し、溶剤を除去しながら混合し、平均粒子径３０μｍの
成形粉を得た。これを８０℃に加熱した金型に投入し８
００kg/cm³の押し圧力で１５分成形し厚さ４mmで直径が
２８５mmの円盤状成形体を得た。この成形体に直径０．
８mmの貫通小孔を３mmのピッチで多数穿孔し、図２に示
す形状の加工をした後、１６０℃までを５℃／時間で昇
温し、１６０℃で３日間保持し硬化処理を行ない、次い
で環状炉に入れ窒素気流中で１３００℃の温度で焼成炭
化した後、高純度の雰囲気炉を用い不活性雰囲気下で２
０００℃の温度で高温処理を行ないガラス状炭素とし
た。得られたガラス状炭素製のプラズマエッチング電極
板の不純物量は２０ppm以下であった。Embodiments of the present invention will be described below. Example 1 Using ammonia as an alkali catalyst, heating at 70 ° C. for 1 hour, 940 parts by weight of phenol and 3 parts of formaldehyde were used.
By reacting 60 parts by weight, a liquid phenol resin having the physical properties shown in Table 1 was obtained. On the other hand, powdered phenolic resin is prepared by injecting the above resin into a mold for 3 days at 50 ° C, 3 days at 70 ° C, 90 ° C.
After drying and curing for 3 days, the average particle size is 11 μm with a crusher.
It was crushed to obtain. 60 parts by weight of a powdery phenolic resin was added to 40 parts by weight (solid content) of the liquid phenolic resin and mixed while removing the solvent to obtain a molding powder having an average particle diameter of 30 μm. Put this in a mold heated to 80 ° C and
It was molded for 15 minutes with a pressing force of 00 kg / cm ³ to obtain a disk-shaped molded product having a thickness of 4 mm and a diameter of 285 mm. This molded body has a diameter of 0.
After making a large number of 8 mm through small holes at a pitch of 3 mm and processing the shape shown in FIG. 2, the temperature is raised up to 160 ° C. at 5 ° C./hour and held at 160 ° C. for 3 days to carry out a hardening treatment. Then, after putting it in a ring furnace and calcining and carbonizing at a temperature of 1300 ° C. in a nitrogen stream, a high-purity atmosphere furnace was used to carry out 2 in an inert atmosphere.
High temperature treatment was performed at a temperature of 000 ° C. to obtain glassy carbon. The amount of impurities in the obtained glass-like carbon plasma-etched electrode plate was 20 ppm or less.

【００１３】次に得られた電極板を図１に示す構造のプ
ラズマエッチング装置に取付け、反応ガス：トリフロロ
メタン、キャリアガス：アルゴン、反応チャンバー内の
ガス圧：１Torr、電源周波数：１３．５MHzの条件で直
径６インチのシリコンウェハの酸化膜エッチングを行っ
た。このときのシリコンウェハの表面に付着した０．１
５μｍ以上の粉末粒子の個数を数えた。この結果をパー
ティクル数として合わせて表１に示す。なお、数平均分
子量は、ゲルパーミエーションクロマトグラフィ法によ
り測定し標準ポリスチレン換算で決定した。検出装置は
日本分析工業(株)製、ＲＩ−３Ｈを用い、カラムとして
はゲルパックＲ４２０、Ｒ４３０及びＲ４４０（いずれ
も日立化成工業(株)製）を直列につないで用いた。Next, the obtained electrode plate was attached to the plasma etching apparatus having the structure shown in FIG. 1, and reaction gas: trifluoromethane, carrier gas: argon, gas pressure in the reaction chamber: 1 Torr, power supply frequency: 13.5 MHz. Under the above conditions, a silicon wafer having a diameter of 6 inches was etched with an oxide film. 0.1 attached to the surface of the silicon wafer at this time
The number of powder particles of 5 μm or more was counted. The results are also shown in Table 1 as the number of particles. The number average molecular weight was measured by gel permeation chromatography and determined in terms of standard polystyrene. RI-3H manufactured by Nippon Analytical Industry Co., Ltd. was used as a detection device, and gel packs R420, R430 and R440 (all manufactured by Hitachi Chemical Co., Ltd.) were connected in series as columns.

【００１４】実施例２ アルカリ触媒としてアンモニアを用いて、８０℃の加熱
下１．５時間フェノール９４０重量部とホルムアルデヒ
ド３６０重量部を反応させ、表１に示す物性の液状フェ
ノール樹脂を得た。一方、粉末状フェノール樹脂は、上
記樹脂を、型に注入し５０℃で３日、７０℃で３日、９
０℃で３日乾燥硬化した後、粉砕機にて平均粒子径２７
μｍに粉砕して得た。前記液状フェノール樹脂４０重量
部（固形分）に粉末状フェノール樹脂６０重量部を添加
し、溶剤を除去しながら混合し、平均粒子径３０μｍの
成形粉を得た。これを８０℃に加熱した金型に投入し８
００kg/cm³の押し圧力で１５分成形し厚さ４mmで直径が
２８５mmの円盤状成形体を得た。この成形体に直径０．
８mmの貫通小孔を３mmのピッチで多数穿孔し、図２に示
す形状の加工をした後、１６０℃までを５℃／時間で昇
温し、１６０℃で３日間保持し硬化処理を行ない、次い
で環状炉に入れ窒素気流中で１３００℃の温度で焼成炭
化した後、高純度の雰囲気炉を用い不活性雰囲気下で２
０００℃の温度で高温処理を行ないガラス状炭素とし
た。得られたガラス状炭素製のプラズマエッチング電極
板の不純物量は２０ppm以下であった。Example 2 Using ammonia as an alkali catalyst, 940 parts by weight of phenol and 360 parts by weight of formaldehyde were reacted under heating at 80 ° C. for 1.5 hours to obtain a liquid phenol resin having the physical properties shown in Table 1. On the other hand, powdered phenolic resin is injected into the mold with the above resin for 3 days at 50 ° C, 3 days at 70 ° C for 9 days.
After drying and hardening at 0 ° C for 3 days, the average particle size is 27 with a crusher.
It was obtained by crushing to μm. 60 parts by weight of a powdery phenolic resin was added to 40 parts by weight (solid content) of the liquid phenolic resin and mixed while removing the solvent to obtain a molding powder having an average particle diameter of 30 μm. Put this in a mold heated to 80 ° C and
It was molded for 15 minutes with a pressing force of 00 kg / cm ³ to obtain a disk-shaped molded product having a thickness of 4 mm and a diameter of 285 mm. This molded body has a diameter of 0.
After making a large number of 8 mm through small holes at a pitch of 3 mm and processing the shape shown in FIG. 2, the temperature is raised up to 160 ° C. at 5 ° C./hour and held at 160 ° C. for 3 days to carry out a hardening treatment. Then, after putting it in a ring furnace and calcining and carbonizing at a temperature of 1300 ° C. in a nitrogen stream, a high-purity atmosphere furnace was used to carry out 2 in an inert atmosphere.
High temperature treatment was performed at a temperature of 000 ° C. to obtain glassy carbon. The amount of impurities in the obtained glass-like carbon plasma-etched electrode plate was 20 ppm or less.

【００１５】次に得られた電極板を図１に示す構造のプ
ラズマエッチング装置に取付け、反応ガス：トリフロロ
メタン、キャリアガス：アルゴン、反応チャンバー内の
ガス圧：１Torr、電源周波数：１３．５MHzの条件で直
径６インチのシリコンウェハの酸化膜エッチングを行っ
た。このときのシリコンウェハの表面に付着した０．１
５μｍ以上の粉末粒子の個数を数えた。この結果をパー
ティクル数として合わせて表１に示す。Next, the obtained electrode plate was attached to the plasma etching apparatus having the structure shown in FIG. 1, and reaction gas: trifluoromethane, carrier gas: argon, gas pressure in the reaction chamber: 1 Torr, power supply frequency: 13.5 MHz. Under the above conditions, a silicon wafer having a diameter of 6 inches was etched with an oxide film. 0.1 attached to the surface of the silicon wafer at this time
The number of powder particles of 5 μm or more was counted. The results are also shown in Table 1 as the number of particles.

【００１６】実施例３ 実施例１で得られた樹脂４０重量部（固形分）に、平均
粒径１９μｍの粉末状フェノール樹脂（鐘紡(株)製ベル
パールＲ−８００）を６０重量部添加し、溶剤を除去し
ながら混合し、平均粒子径３０μｍの成形粉を得た。こ
れを８０℃に加熱した金型に投入し８００kg/cm³の押し
圧力で１５分成形し厚さ４mmで直径が２８５mmの円盤状
成形体を得た。この成形体に直径０．８mmの貫通小孔を
３mmのピッチで多数穿孔し、図２に示す形状の加工をし
た後、１６０℃までを５℃／時間で昇温し、１６０℃で
３日間保持し硬化処理を行ない、次いで環状炉に入れ窒
素気流中で１３００℃の温度で焼成炭化した後、高純度
の雰囲気炉を用い不活性雰囲気下で２０００℃の温度で
高温処理を行ないガラス状炭素とした。得られたガラス
状炭素製のプラズマエッチング電極板の不純物量は２０
ppm以下であった。Example 3 To 40 parts by weight (solid content) of the resin obtained in Example 1 was added 60 parts by weight of powdered phenolic resin (Bellpearl R-800 manufactured by Kanebo Co., Ltd.) having an average particle size of 19 μm. Mixing was performed while removing the solvent to obtain a molding powder having an average particle diameter of 30 μm. This was placed in a mold heated to 80 ° C. and molded for 15 minutes with a pressing force of 800 kg / cm ³ to obtain a disk-shaped molded body having a thickness of 4 mm and a diameter of 285 mm. A large number of through-holes with a diameter of 0.8 mm were perforated in this molded body at a pitch of 3 mm, and the shape shown in FIG. 2 was processed. After holding and hardening treatment, it was put into an annular furnace and calcined and carbonized at a temperature of 1300 ° C. in a nitrogen stream, and then high-temperature treatment was carried out at a temperature of 2000 ° C. in an inert atmosphere using a high-purity atmosphere furnace to obtain glassy carbon. And The amount of impurities in the obtained glass-like carbon plasma-etched electrode plate was 20.
It was below ppm.

【００１７】次に得られた電極板を図１に示す構造のプ
ラズマエッチング装置に取付け、反応ガス：トリフロロ
メタン、キャリアガス：アルゴン、反応チャンバー内の
ガス圧：１Torr、電源周波数：１３．５MHzの条件で直
径６インチのシリコンウェハの酸化膜エッチングを行っ
た。このときのシリコンウェハの表面に付着した０．１
５μｍ以上の粉末粒子の個数を数えた。この結果をパー
ティクル数として合わせて表１に示す。The electrode plate thus obtained was attached to a plasma etching apparatus having the structure shown in FIG. 1, and reaction gas: trifluoromethane, carrier gas: argon, gas pressure in the reaction chamber: 1 Torr, power supply frequency: 13.5 MHz. Under the above conditions, a silicon wafer having a diameter of 6 inches was etched with an oxide film. 0.1 attached to the surface of the silicon wafer at this time
The number of powder particles of 5 μm or more was counted. The results are also shown in Table 1 as the number of particles.

【００１８】実施例４ 実施例２で得られた樹脂４０重量部（固形分）に、平均
粒径１９μｍの粉末状フェノール樹脂（鐘紡(株)製ベル
パールＲ−８００）を６０重量部添加し、溶剤を除去し
ながら混合し、平均粒子径３０μｍの成形粉を得た。こ
れを８０℃に加熱した金型に投入し８００kg/cm³の押し
圧力で１５分成形し厚さ４mmで直径が２８５mmの円盤状
成形体を得た。この成形体に直径０．８mmの貫通小孔を
３mmのピッチで多数穿孔し、図２に示す形状の加工をし
た後、１６０℃までを５℃／時間で昇温し、１６０℃で
３日間保持し硬化処理を行ない、次いで環状炉に入れ窒
素気流中で１３００℃の温度で焼成炭化した後、高純度
の雰囲気炉を用い不活性雰囲気下で２０００℃の温度で
高温処理を行ないガラス状炭素とした。得られたガラス
状炭素製のプラズマエッチング電極板の不純物量は２０
ppm以下であった。Example 4 To 40 parts by weight (solid content) of the resin obtained in Example 2, 60 parts by weight of a powdery phenolic resin having an average particle diameter of 19 μm (Bellpearl R-800 manufactured by Kanebo Co., Ltd.) was added, Mixing was performed while removing the solvent to obtain a molding powder having an average particle diameter of 30 μm. This was placed in a mold heated to 80 ° C. and molded for 15 minutes with a pressing force of 800 kg / cm ³ to obtain a disk-shaped molded body having a thickness of 4 mm and a diameter of 285 mm. A large number of through-holes with a diameter of 0.8 mm were perforated in this molded body at a pitch of 3 mm, and the shape shown in FIG. 2 was processed. After holding and hardening treatment, it was put into an annular furnace and calcined and carbonized at a temperature of 1300 ° C. in a nitrogen stream, and then high-temperature treatment was carried out at a temperature of 2000 ° C. in an inert atmosphere using a high-purity atmosphere furnace to obtain glassy carbon. And The amount of impurities in the obtained glass-like carbon plasma-etched electrode plate was 20.
It was below ppm.

【００１９】次に得られた電極板を図１に示す構造のプ
ラズマエッチング装置に取付け、反応ガス：トリフロロ
メタン、キャリアガス：アルゴン、反応チャンバー内の
ガス圧：１Torr、電源周波数：１３．５MHzの条件で直
径６インチのシリコンウェハの酸化膜エッチングを行っ
た。このときのシリコンウェハの表面に付着した０．１
５μｍ以上の粉末粒子の個数を数えた。この結果をパー
ティクル数として合わせて表１に示す。The electrode plate thus obtained was attached to a plasma etching apparatus having the structure shown in FIG. 1, and reaction gas: trifluoromethane, carrier gas: argon, gas pressure in the reaction chamber: 1 Torr, power supply frequency: 13.5 MHz. Under the above conditions, a silicon wafer having a diameter of 6 inches was etched with an oxide film. 0.1 attached to the surface of the silicon wafer at this time
The number of powder particles of 5 μm or more was counted. The results are also shown in Table 1 as the number of particles.

【００２０】比較例１〜４ 実施例１と同様の原料から製造した、表２に示す物性の
液状フェノール樹脂を用いたほかは、実施例１と同様に
製造してプラズマエッチング用電極板を作成し評価し
た。表２にその特性を示した。Comparative Examples 1 to 4 Plasma electrode plates for plasma etching were prepared in the same manner as in Example 1 except that the liquid phenol resin having the physical properties shown in Table 2 prepared from the same raw materials as in Example 1 was used. And evaluated. Table 2 shows the characteristics.

【００２１】比較例５ 実施例１で用いた液状フェノール樹脂を１００重量部と
し、粉末状フェノール樹脂を用いずに硬化した後、実施
例１と同様の処理を行いプラズマエッチング用電極板を
作成し評価した。表２にその特性を示した。 比較例６ 従来材としてフラン樹脂（日立化成工業(株)製ヒタフラ
ンＶＦ−３０３）にパラトルエンスルホン酸５０重量％
水溶液０．６重量部を加えて硬化した後、実施例１と同
様の処理をして得られたプラズマエッチング用電極板の
特性を表２に示した。Comparative Example 5 The liquid phenol resin used in Example 1 was used as 100 parts by weight, and the liquid phenol resin was cured without using the powdery phenol resin. Then, the same treatment as in Example 1 was carried out to prepare an electrode plate for plasma etching. evaluated. Table 2 shows the characteristics. Comparative Example 6 As a conventional material, furan resin (Hitafuran VF-303 manufactured by Hitachi Chemical Co., Ltd.) was added to paratoluenesulfonic acid 50% by weight.
Table 2 shows the characteristics of the electrode plate for plasma etching obtained by adding 0.6 part by weight of an aqueous solution and curing the same, and then performing the same treatment as in Example 1.

【００２２】[0022]

【表１】 [Table 1]

【００２３】[0023]

【表２】 [Table 2]

【００２４】[0024]

【発明の効果】請求項１記載のプラズマエッチング用電
極板は、エッチングの際に発生する有害な炭素微粒子の
数が大幅に少なく、長時間の使用が可能であり、トラブ
ルのない安定なエッチング加工を行なうことできる。請
求項２記載のプラズマエッチング用電極板は、請求項１
記載のプラズマエッチング用電極板の効果を奏し、特に
寿命に優れる。請求項３記載のプラズマエッチング用電
極板は、請求項１記載のプラズマエッチング用電極板の
効果を奏し、特に安定性に優れる。EFFECT OF THE INVENTION The plasma etching electrode plate according to claim 1 has a significantly small number of harmful carbon fine particles generated during etching, can be used for a long time, and has stable etching processing without trouble. Can be done. The electrode plate for plasma etching according to claim 2 is the electrode plate according to claim 1.
The effect of the electrode plate for plasma etching described above is exhibited, and the life is particularly excellent. The electrode plate for plasma etching according to the third aspect has the effect of the electrode plate for plasma etching according to the first aspect, and is particularly excellent in stability.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明のプラズマエッチング用電極板を取り付
けたプラズマエッチング装置の概略図である。FIG. 1 is a schematic view of a plasma etching apparatus equipped with a plasma etching electrode plate of the present invention.

【図２】本発明のプラズマエッチング用電極板の一例の
正面図である。FIG. 2 is a front view of an example of a plasma etching electrode plate of the present invention.

【符号の説明】[Explanation of symbols]

１…プラズマエッチング用電極板（上部電極） ２…下部電極 ３…シリコンウェハ ４…ガス吹出穴 1 ... Electrode plate for plasma etching (upper electrode) 2 ... Lower electrode 3 ... Silicon wafer 4 ... Gas blowout hole

Claims (3)

【特許請求の範囲】[Claims] 【請求項１】 数平均分子量が２５０〜３５０であり、
２５℃における粘度が１００〜３５０センチポイズの液
状フェノール樹脂と粉末状フェノール樹脂の混合物を原
料とするガラス状炭素を基材とするプラズマエッチング
用電極板。1. A number average molecular weight of 250 to 350,
An electrode plate for plasma etching using glassy carbon as a base material, which is made of a mixture of a liquid phenol resin having a viscosity of 100 to 350 centipoise at 25 ° C. and a powdery phenol resin. 【請求項２】 基材の見掛け密度が１．５０〜１．５５
g/cm³、不純物含有量が２０ppm以下である請求項１記載
のプラズマエッチング用電極板。2. The apparent density of the substrate is 1.50 to 1.55.
The electrode plate for plasma etching according to claim 1, which has g / cm ³ and an impurity content of 20 ppm or less. 【請求項３】 基材の気孔径が５μｍ以下である請求項
１又は２記載のプラズマエッチング用電極板。3. The electrode plate for plasma etching according to claim 1, wherein the pore diameter of the base material is 5 μm or less.